title: Combination of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging is an optimal way to evaluate rheumatoid arthritisin rats dynamically.
abstract: BACKGROUND
  Rheumatoid arthritis (RA) is a chronic, systemic autoimmune inflammatory disorder. Many methods have been used to observe the progress of RA. The purpose of this study was to observe the progress of RA in rats with 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), magnetic resonance (MR) imaging and arthritis score, and analyze the relationships among different methods in evaluation of RA.
  
  
  METHODS
  Sixteen healthy Sprague Dawley (SD) rats about 8-week old were randomly assigned to a RA group and a control group. Bovine type II emulsified incomplete Freud's adjuvant was used to induce arthritis in the RA group. Arthritis score of the rats in two groups were recorded, and (18)F-FDG PET/CT, MR imaging were performed both on the corresponding rats every 3 days. All the rats were sacrificed at week 5, and histopathological examination was performed on rat knees stained with haematoxylin and eosin.
  
  
  RESULTS
  The arthritis score and the standard uptake value (SUV) of knee joints in RA rats increased with the progression of arthritis gradually. Both peaks of arthritis score and SUV appeared at 21 days after the first immune injection, then the arthritis score and SUV of knee joints decreased slowly. The arthritis scores of knee joints in RA rats were positively correlated with their SUV changes. The MR images were confirmed by the histopathological studies.
  
  
  CONCLUSIONS
  PET/CT can detect the earliest molecular metabolism changes of RA, and MR imaging can follow up the dynamical anatomical changes of RA, all of which indicated that PET/CT and MR imaging may be applied as useful tools to monitor the progress of RA.
authors.affiliation: Department of Radiology, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Wei-Tao
authors.initials: WT
authors.lastname: Zhang
authors.forename: Xiang-Ke
authors.initials: XK
authors.lastname: DU
authors.forename: Tian-Long
authors.initials: TL
authors.lastname: Huo
authors.forename: Zheng-Mao
authors.initials: ZM
authors.lastname: Wei
authors.forename: Chuan-Xi
authors.initials: CX
authors.lastname: Hao
authors.forename: Bei
authors.initials: B
authors.lastname: An
mesh_terms: D000818:Animals; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000473:pathology; D019788:Fluorodeoxyglucose F18; D008279:Magnetic Resonance Imaging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D051381:Rats; D017207:Rats, Sprague-Dawley; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18